D-aspartic acid
D-aspartic acid suppliers and sourcing guide
D-aspartic acid is the D-enantiomer (mirror-image form) of aspartic acid. Commercial material is made by resolving racemic DL-aspartic acid or by enzymatic processes that remove the L-form, then crystallized. Brands buy it as a white crystalline powder, as the free acid or as salts such as sodium D-aspartate and calcium D-aspartate, mostly for capsules and powders.
- Category
- Proteins and amino acids
- Also known as
- D-Asp · (R)-Aminobutanedioic acid · DAA · Sodium D-aspartate · Calcium D-aspartate
- Facts checked
- November 2026
Forms and grades of d-aspartic acid
Suppliers sell different products under the same name. Specify the one you need.
Free acid
Crystalline D-aspartic acid, the most common form for capsules and powders.
Sodium D-aspartate
The sodium salt, more water-soluble than the free acid; calculate D-aspartic acid content and sodium from the salt.
Calcium D-aspartate
Calcium D-aspartate trihydrate, a salt form listed by Health Canada; calculate D-aspartic acid content from the salt.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Identity and optical purity
- Infrared spectrum matched to a reference standard, plus specific optical rotation or chiral HPLC to confirm the D-form and show how much L-aspartic acid remains.
- Assay
- Purity on a dried basis by titration or HPLC, reported against the supplier specification (there is no USP monograph for the D-form).
- Related substances
- Other amino acids and residual fumaric or maleic acid by HPLC.
- Loss on drying and residue on ignition
- Moisture by loss on drying and inorganic residue as residue on ignition, with sodium or calcium content for salt forms.
- Heavy metals and microbiology
- Lead, arsenic, cadmium and mercury by ICP-MS, plus total plate count, yeast and mold, E. coli and Salmonella.
Storage, lots and expiry
Storage and shelf life
Store D-aspartic acid in tightly closed, lined containers in a cool, dry place away from light and strong odors, and reseal opened packs promptly. Shelf life or retest date is set by the supplier's specification; assay, loss on drying and micro are the usual retest points for older stock.
Lots and expiry dates
Record assay, optical purity and salt form for each lot, since L-aspartic acid content is the main way lots differ. Rotate stock FEFO.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
Health Canada's Natural Health Products Ingredients Database lists D-aspartic acid as an approved chemical name, classified as a natural health product under Schedule 1, item 2 (an isolate).
Source: webprod.hc-sc.gc.ca (opens in a new tab)The same database entry lists calcium D-aspartate trihydrate and sodium D-aspartate as source ingredients.
Source: webprod.hc-sc.gc.ca (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
D-aspartic acid suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking d-aspartic acid suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell d-aspartic acid? Request a listingFrequently asked questions
What forms of d-aspartic acid can brands buy?
Common forms include free acid, sodium D-aspartate and calcium D-aspartate. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for d-aspartic acid include?
Expect identity and optical purity, assay, related substances, loss on drying and residue on ignition and heavy metals and microbiology, each with its method, specification and result for that lot.
How should d-aspartic acid be stored?
Store D-aspartic acid in tightly closed, lined containers in a cool, dry place away from light and strong odors, and reseal opened packs promptly. Shelf life or retest date is set by the supplier's specification; assay, loss on drying and micro are the usual retest points for older stock.
What is the regulatory status of d-aspartic acid?
Health Canada's Natural Health Products Ingredients Database lists D-aspartic acid as an approved chemical name, classified as a natural health product under Schedule 1, item 2 (an isolate). The same database entry lists calcium D-aspartate trihydrate and sodium D-aspartate as source ingredients.
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